class App extends React.Component{
    constructor(props) {
        super(props)
        this.state = {
            name: 'abin'
        }
        
    }

    render() {
        return <Child />
    }
}

class Child extends React.Component{
    constructor(props) {
        super(props)
        this.state = {
            childName: 'abinchild'
        }
        
    }
    
    render() {
        return <h1>test class child</h1>
    }
}
debugger;
ReactDOM.render(<App />, document.querySelector('#app'));
